Needle-septum interface for a fluidic analyzer

ABSTRACT

Instrument-cartridge interfaces for fluidic analyzers that have an instrument and a removable cartridge are disclosed. For example, and in one illustrative embodiment, the instrument may include a needle that is adapted to penetrate a septum on a removable cartridge. In another illustrative embodiment, the instrument may include a plunger that is adapted to deform a deformable membrane on a removable cartridge. In yet another illustrative embodiment, the instrument may include a nozzle that is adapted to mate and seal with a flow channel on a removable cartridge. Techniques for detecting the flow rate in a flow channel on a removable cartridge, as well as the position of fluid in a flow channel of a removable cartridge, are also disclosed.

FIELD

The present invention relates generally to fluidic analyzers, and moreparticularly, to fluidic analyzers that have an instrument-cartridgeinterface.

BACKGROUND

Chemical and/or biological analysis is important for life sciencesresearch, clinical diagnostics and a wide range of environmental andprocess monitoring. In some cases, an analyzer is used to perform and/orassist in performing a chemical and/or biological analysis of a samplefluid. The sample fluid may be a liquid or a gas, depending on theapplication.

Some analyzers include an instrument that receives a removable, and insome cases, a disposable cartridge. In such analyzers, a sample fluid isoften introduced or otherwise provided to the removable cartridge, andthe instrument, through one or more interfaces, interacts with theremovable cartridge to help perform and/or control the desired chemicaland/or biological analysis. The interfaces may include, for example,fluid interfaces, electrical interfaces and/or other types ofinterfaces, depending on the application. The integrity of theinterfaces is often important to the functioning of the overall device.For example, fluid interfaces often convey one or more fluids (eitherliquid or gas fluids) between the removable cartridge and theinstrument, and/or visa-versa, and it is often desirable for the fluidinterfaces to be substantially leak-free, reliable and cost effective.

SUMMARY

The following summary of the invention is provided to facilitate anunderstanding of some of the innovative features unique to the presentinvention and is not intended to be a full description. A fullappreciation of the invention can be gained by taking the entirespecification, claims, drawings, and abstract as a whole.

The present invention relates generally to fluidic analyzers, and moreparticularly, to fluidic analyzers that have one or moreinstrument-cartridge interfaces. In some embodiments, the fluidicanalyzer may be a flow cytometer and/or hematology analyzer having oneor more leak-free interfaces between an instrument and a disposablecartridge, but other fluidic analyzers may be used as well.

In one illustrative embodiment, a fluidic analyzer is provided thatincludes a cartridge that has a first flow channel defined by flowchannel walls, and an opening that extends from outside of the cartridgeand into the first flow channel. A septum is disposed in or over theopening and is secured to at least a portion of the cartridge with afluid tight seal. An instrument is also provided for receiving thecartridge. A first needle may be attached to the instrument. The firstneedle may be sized to fit in the opening of the first flow channel ofthe cartridge, and pierce through the septum. With the first needlesituated in the opening of the first flow channel and through theseptum, the instrument may induce a flow in the first needle, which inturn, induces a flow in the first flow channel of the cartridge. In somecases, the instrument may include a sensor or the like to sense the flowinduced in the first needle. The flow induced in the first needle may berelated to the flow induced in the first flow channel of the cartridge.

The septum may be adapted to provide a relatively fluid tight sealaround the first needle when the first needle pierces and extendsthrough the septum. Alternatively, or in addition, the septum may beadapted to reseal the opening after withdrawal of the first needle fromthe septum.

In some cases, the first needle may include a body, a tip, and astopping mechanism. The stopping mechanism may be disposed around atleast part of the body of the first needle and offset back from the tipof the first needle by a distance. The stopping mechanism may be offsetby a distance that allows the tip of the first needle to pierce throughthe septum, but prevents the tip of the first needle from engaging aback side of the first flow channel of the cartridge.

In some embodiments, the cartridge includes a second flow channel, andthe instrument includes a second needle that passes fluid between thesecond flow channel of the cartridge and the instrument. In some cases,the second needle is in fluid communication with the first needle via afluid pathway of the instrument. The instrument may include a flowsensor for sensing the fluid flow in the fluid pathway of theinstrument, if desired. In other cases, the second needle may provide anindependently controlled pressure to the cartridge. In some embodiments,the cartridge may include the first and/or second needle, and theinstrument may include one or more corresponding septums, as desired.

In another illustrative embodiment, a fluidic analyzer is provided thatincludes a cartridge with a flow channel defined by flow channel walls,and an opening that extends from outside of the cartridge and into theflow channel. A resilient and/or flexible membrane may be disposed in orover the opening and secured to at least a portion of the cartridge viaa fluid tight seal. The fluid analyzer may further include an instrumentfor receiving the cartridge. The instrument may have a plunger that isin registration with the resilient and/or flexible membrane of thecartridge when the cartridge is received by the instrument. Theinstrument may further have a moving mechanism that moves at least anend of the plunger into engagement with the resilient and/or flexiblemembrane of the cartridge so as to deform the resilient and/or flexiblemembrane, which changes the volume of a fluid chamber on the cartridge,which in turn, induces a flow in the flow channel of the cartridge.

The plunger may be any type of plunger. For example, the plunger mayinclude a rigid end, and the moving mechanism of the instrument may movethe rigid end of the plunger toward the resilient and/or flexiblemembrane to deform the resilient and/or flexible membrane.Alternatively, the plunger may include a deformable resilient and/orflexible membrane, and the moving mechanism of the instrument mayinclude a pressure source that creates a pressure behind the resilientand/or flexible membrane of the plunger end to deform the resilientand/or flexible membrane of the plunger end toward the resilient and/orflexible membrane of the cartridge. This, in turn, deforms the resilientand/or flexible membrane of the cartridge, and ultimately, induces aflow in the flow channel of the cartridge.

In another illustrative embodiment, a fluidic analyzer is provided thatincludes a cartridge that has a first major surface and an opposingsecond major surface, with a flow channel positioned between the firstmajor surface and the second major surface. The cartridge may furtherhave an opening extending through the first major surface and into thefirst flow channel. The fluidic cartridge may further have an instrumentfor receiving the cartridge. The instrument may have a pressure sourcethat is at least selectively in fluid communication with a nozzle. Thepressure source may be any type of pressure source that produces eitherpositive or negative pressure. The nozzle is positioned over the openingin the cartridge and forms a substantially fluid tight seal therewithwhen the cartridge is received by the instrument. The instrument maycontrol the pressure of the pressure source so that a desired flow isinduced in the flow channel of the cartridge via the nozzle/openinginterface. In some embodiments, the cartridge may include a one-wayvalve in the opening or the flow channel, which may help prevent fluidfrom exiting the cartridge when the cartridge is removed from theinstrument.

In yet another illustrative embodiment, a fluidic cartridge is providedthat has a cartridge with a chamber defined by one or more chamberwalls. The fluidic cartridge may further have an instrument thatreceives the cartridge. The instrument may have a force mechanism forapplying a force to the cartridge that deforms at least part of one ormore of the chamber walls to induce a flow in the cartridge. In somecases, the at least part of the one or more chamber walls that isdeformed includes a flexible membrane that deforms under the appliedforce, thereby changing the volume of the chamber and inducing a flow ina fluid channel of the cartridge. In other cases, the at least part ofthe one or more chamber walls that is deformed is a relatively rigidwall that collapses under the applied force, thereby changing the volumeof the chamber of the cartridge. The force mechanism may be any type offorce mechanism. For example, the force mechanism may include a rollerthat when rolled along the cartridge, at least part of one or more ofthe chamber walls is deformed (e.g. compressed) by the roller to inducea flow in the cartridge.

In another illustrative embodiment, a fluidic cartridge is provided thatincludes a disposable cartridge that has a flow channel for transportinga fluid down the flow channel, wherein the fluid has one or moredetectable characteristics. The fluidic cartridge also includes aninstrument for receiving the disposable cartridge. The instrument mayhave a first detector situated at a first location along the flowchannel for detecting at least one of the one or more detectablecharacteristics of the fluid. The instrument may use the detection ofthe one or more detectable characteristics of the fluid by the firstdetector to determine a measure of flow rate of the fluid in the flowchannel of the cartridge and/or a current position of the fluid in theflow channel. The instrument may further have a second detector,positioned at a second location along the flow channel spaced downstreamof the first location, for detecting at least one of the one or moredetectable characteristics of the fluid. The instrument may use thedetection of the one or more detectable characteristics of the fluid bythe first detector and the second detector to determine a measure offlow rate of the fluid in the flow channel and/or a current position ofthe fluid in the flow channel. The fluid that is detected may be asample fluid of interest, a pusher fluid for pushing a sample fluid ofinterest along the flow channel, or any other fluid as desired.

BRIEF DESCRIPTION

FIG. 1 is a perspective view of an illustrative portable cytometer;

FIG. 2 is a schematic partial cross-sectional side view of anillustrative fluidic analyzer that includes a needle in aninstrument/cartridge interface;

FIG. 3 is a schematic partial cross-sectional side view of theillustrative embodiment of FIG. 2 with a flow sensor in line with theneedle;

FIG. 4 is a schematic view of another illustrative fluidic analyzer thatincludes two (or more) needles in the instrument/cartridge interface;

FIG. 5 is a schematic partial cross-sectional side view of anotherillustrative instrument/cartridge interface;

FIG. 6 is a schematic partial cross-sectional side view of yet anotherillustrative instrument/cartridge interface;

FIG. 7 is a schematic partial cross-sectional side view of anotherillustrative instrument/cartridge interface;

FIG. 8 is a schematic partial cross-sectional side view of anillustrative embodiment for determining a flow rate on a cartridge;

FIG. 9 is a schematic partial cross-sectional side view of anotherillustrative embodiment for determining a flow rate on a cartridge;

FIG. 10 is a schematic partial cross-sectional side view of anillustrative fluidic analyzer that includes a cartridge with acollapsible flow channel and an instrument with a roller forcontrollably collapsing the flow channel;

FIG. 11 is a schematic partial cross-sectional side view of anotherillustrative fluidic analyzer that has a cartridge with a collapsibleflow channel and an instrument with a roller for controllably collapsingthe flow channel;

FIG. 12 is a schematic top view of a cartridge that includes a number ofgears for inducing a flow in a flow channel of the cartridge;

FIG. 13 is a schematic view of an illustrative fluidic analyzer thatincludes an instrument with a detector for determining the flow rateand/or current position of a fluid in a flow channel of a cartridge; and

FIGS. 14A-14B are schematic views of an illustrative fluidic analyzerthat includes an instrument with two (or more) detectors for determiningthe flow rate and/or current position of a fluid in a flow channel of acartridge.

DETAILED DESCRIPTION

The following description should be read with reference to the drawingswherein like reference numerals indicate like elements throughout theseveral views. The detailed description and drawings show severalembodiments which are meant to be illustrative of the claimed invention.

The present invention relates generally to fluidic analyzers, and moreparticularly, to fluidic analyzers that have one or more fluidicinstrument-cartridge interfaces. In some embodiments, the fluidicanalyzer may be a flow cytometer, a hematology analyzer, a clinicalchemistry analyzer (e.g. glucose analyzer, ion analyzer, electrolytesanalyzer, dissolved gasses analyzer, etc.), a urine analysis analyzer orany other suitable analyzer having one or more leak-free interfacesbetween an instrument and a disposable cartridge.

FIG. 1 is a perspective view of an illustrative portable cytometer. Theillustrative cytometer 10 includes an instrument 12 and a removable, andin some cases, disposable cartridge 14. The illustrative instrument 12includes a base 16, a cover 18, and a hinge 20 that attaches the base 16to the cover 18. The base 16 may include light sources 22 a and 22 b,along with associated optics and the necessary electronics for operationof the cytometer. The cover 12 may include light detectors 24 a and 24 bwith associated optics.

The removable cartridge 14 may receive a sample fluid, such as, forexample, a blood sample, via a sample collector port 32. A cap 38 may beused to protect the sample collector port 32 when the removablecartridge 14 is not in use. The removable cartridge 14 may perform blooddilution, red cell lysing, and hydrodynamic focusing for core formation.The removable cartridge 14 may be constructed similar to the fluidiccircuits available from Micronics Technologies, some of which arefabricated using a laminated structure with etched channels.

During use, the removable cartridge 14 is inserted into the instrumentwhen the cover 18 is in the open position. The removable cartridge 14may include holes 26 a and 26 b for receiving registration pins 28 a and28 b in the base 16, which may help provide alignment and couplingbetween the different parts. The removable cartridge 14 also mayincludes transparent flow stream windows 30 a and 30 b, which are inalignment with the arrays of the light sources 22 a and 22 b, and lightdetectors 24 a and 24 b.

To initiate a test, the cover 18 may be lifted and a new cartridge 14may be placed and registered onto the base 16. A sample fluid isintroduced into the sample collector 32. The cover 18 is then closed. Insome cases, the removable cartridge 14 provides blood dilution, red celllysing, and hydrodynamic focusing for core formation. In some cases, theinstrument 12 performs a white blood cell cytometry measurement. Forexample, the light sources 22 a and 22 b, light detectors 24 a and 24 band associated control and processing electronics may performdifferentiation and counting of white blood cells based on lightscattering and/or fluorescent signals. Rather than using a hingedconstruction for the housing 12, it is contemplated that a slidingcartridge slot or any other suitable construction may be used, asdesired.

To perform such an analysis, the sample fluid (e.g. blood sample) mayneed to be pushed (or pulled) through one or more flow channels of thecartridge 14. Reagents and/or other fluids may also need to be pushed(or pulled) through one or more flow channels. In some cases, theinstrument 12 may aid in creating the necessary flows in the cartridgethough one or more instrument/cartridge interfaces. Alternatively, or inaddition, the instrument 12 may be used to monitor and/or control theflows on the cartridge.

FIG. 2 is a schematic partial cross-sectional side view of anillustrative fluidic analyzer that includes a needle in aninstrument/cartridge interface. In the illustrative embodiment, acartridge 41 is shown as having a flow channel 48, defined by flowchannel walls. The flow channel 48 is provided between an upper majorsurface 43 and a lower major surface 45 of the cartridge 41. In somecases, the flow channel 48 may be a long, thin flow channel in thecartridge 41. However, it is contemplated that the flow channel 48 maytake on any suitable size or shape, as desired. In the illustrativeembodiment, an opening 47 is provided between the flow channel 48 andthe upper major surface 43.

A septum 42 is disposed in or over the opening 47 to form a fluid tightseal. In some cases, the septum 42 also extends over all or a portion ofthe upper major surface 43 of the cartridge 41 as shown, but this is notrequired. The septum 42 may prevent or substantially prevent fluid fromflowing through the opening 47 in the flow channel 48 and out of thecartridge 41.

The septum 42 may be adapted to allow an object, such as a needle 40 orany other suitable object, to pierce the septum 42 and become in fluidcommunication with the flow channel 48. The septum 42 may also form aseal around the needle 40 to prevent or substantially prevent fluid frompassing between the outside of the needle 40 and the septum 42. Theseptum 42 may also be adapted to reseal the opening created by theneedle 40 after the needle 40 is removed from the septum 42. In somecases, as the needle 40 is withdrawn, the septum 42 may also wipe theneedle 40 to help remove residual fluid from the needle 40. The septum42 may be made from, for example, a resilient and/or flexible materialsuch as an elastomer (e.g. rubber) or the like.

In the illustrative embodiment, the needle 40 has an elongated-tubularbody with a hollow core to allow fluid to flow therethrough. The bodymay be attached at one end to an instrument. The other end of the needle40 may terminate in a tip 46, which may be adapted for insertion intothe cartridge 41 through the septum 42. In the illustrative embodiment,the tip includes a tapered pointed tip that may allow the needle to moreeasily pierce the septum 42 without coring the septum 42. However, it iscontemplated that any suitable needle 40 tip may be used, as desired.

In some embodiments, the needle 40 may also have a stopping mechanism 44disposed around and secured relative to the body of the needle 40. Thestopping mechanism 44 may extend laterally outward from the body by adistance, and may be offset by an offset distance from the tip 46 of theneedle 40. The stopping mechanism 44 may assist in inserting the needle40 to a consistent and proper depth. In the illustrative embodiment, theneedle 40 may pierce the septum 42 and may move down until the tip 46 ofthe needle is in fluid communication with the flow channel 48 and thestopping mechanism 44 engages the top surface of the septum 42 (orcartridge 41). With the needle 40 fully inserted, the offset distance ofthe stopping mechanism may be set to help ensure that the tip 46 of theneedle 40 does not engage the back side wall 51 of the flow channel 48,when this is desired. Thus, in some illustrative embodiments, thestopping mechanism 44 may help prevent over and under insertion of theneedle 40 into the cartridge.

When inserted, the hollow opening of the needle 40 tip 46 may be used totransfer a fluid and/or a pressure between the instrument (see FIG. 1)and the flow channel 48 of the cartridge 41. In some cases, theinstrument may provide a fluid and/or a pressure that creates a desiredflow in the flow channel 48 of the cartridge 41.

For example, and in some cases, the instrument may have a reservoir offluid thereon. The fluid may be, for example, a reagent fluid, a lysefluid, a sheath fluid, a pusher fluid, or any other suitable fluid, asdesired. The fluid from the instrument may be provided to the flowchannel 48 of the cartridge 41 through the needle 40, and create a flowof fluid in the flow channel 48. In some cases, by knowing the flow rateat which the fluid leaves the instrument, the flow in the flow channel48 may be determined and/or controlled.

It is contemplated that the cartridge 41 may be removable or evendisposable. The removable cartridge 41 may, in some embodiments, beinserted into an instrument that is adapted to receive the cartridge 41.The instrument may include, for example, a base, a cover and a needle41. Once inserted, the cover of the instrument may be closed. In somecases, the needle 40 of the instrument may already be sufficientlyaligned with the septum, while in other cases, the needle 40 may need tobe aligned. Once aligned, the needle 40 may be actuated toward thecartridge 41 and may pierce the septum 42 and move to a position withthe tip 46 of the needle 40 in fluid communication with the flow channel48 of the cartridge 41. In some cases, the actuation or movement of theneedle 40 may be automated, such as by a motor or the like, whichactuates the needle 40 between an inserted position and a withdrawnposition. A controller may be used to control the motor. Alternatively,it is contemplated that the needle 40 may be moved into positionmanually, such as by manually inserting and withdrawing the needle 40from the cartridge 41.

Once the needle 40 is inserted into the cartridge 41 with the opening ofthe tip 46 positioned in the flow channel 48 of the cartridge 41, afluid may be delivered from the instrument to the flow channel 48 of thecartridge 41 at a controlled flow rate. The fluid may be a gas or aliquid fluid, as desired. In the automated process, the flow rate mayalso be controlled by the controller, if desired.

After the needle 40 and instrument deliver the desired fluid to thecartridge 41, the needle 40 may be withdrawn so that the cartridge 41can be removed from the instrument and, in some cases, properly disposedof. Again, the withdrawal of the needle 40 may be automated or manualperformed as desired. In some cases, as the needle 40 is withdrawn fromthe cartridge 41, residual fluid is wiped off the needle 40 by theseptum 42.

In some cases, the fluid flow rate provided by the instrument along withits correlation to the flow rate of the sample in the cartridge 41 canbe determined. This may provide a relatively easy way to accuratelydetermine and/or control the flow rate of the sample fluid in the flowchannel 48 of the cartridge 41.

Prior to a measurement, it is contemplated that the instrument may flushthe body and tip 46 of the needle 40 with a fluid before the needle 40is inserted into the cartridge 41. This may help remove a possiblecontamination source from one cartridge to another. At the end of ameasurement, the outside of the needle 40 body and tip 46 may be wipedoff by the septum 42 during withdrawal, also helping to remove apossible contamination source. Also, the small scale or small surfacearea of the tip 46 of the needle 40 may help reduce the quantity ofsample fluid that may be a source of contamination.

In some cases, a heat sterilization process may be introduced tosterilize the tip 46 of the needle 40 between cartridge measurements.For example, the sterilization process may be a rapid heat and coolcycle similar to that of a heat transfer pin. This process, in somecases, may be provided after each use of the needle 40, as desired. Inaddition, a one way valve may be provided in the instrument and/orcartridge 41, which may help prevent backflow of fluids into theinstrument and/or cartridge 41. This may be particularly useful during aperiod of power loss.

FIG. 3 is a schematic partial cross-sectional side view of theillustrative embodiment of FIG. 2 with a sensor 50 placed in line withthe needle 40. As illustrated, the sensor 50 senses a characteristic ofthe fluid in a supply flow channel 49 of the instrument. The sensor 50may measure, for example, the flow rate, pressure or othercharacteristic of the fluid while the fluid is still in the instrumentor, in other words, before the fluid leaves the instrument through theneedle 40. In one illustrative embodiment, the sensor 50 may be athermal anemometer type flow sensor such as described in, for example,U.S. Pat. No. 4,478,076, U.S. Pat. No. 4,478,077, U.S. Pat. No.4,501,144, U.S. Pat. No. 4,651,564, U.S. Pat. No. 4,683,159, and U.S.Pat. No. 5,050,429, all of which are incorporated herein by reference.However, it is contemplated that the sensor 50 may be any suitable typeof flow sensor, as desired.

By positioning the sensor 50 adjacent the flow channel 49 in theinstrument, the sensor 50 may be able to directly measure the flow rateof the fluid passing through the needle 40. By knowing the flow ratepassing through the needle 40, the flow rate in the flow channel 48 ofthe cartridge may also be determined. Alternatively, or in addition, thesensor 50 may be used to detect one or more characteristics of thefluid, such as thermal conductivity, specific heat, fluid density,electrical resistivity, and/or other characteristics of the fluid to,for example, help identify or verify that the fluid passing through theflow channel 49 is the expected fluid or expected fluid type. This mayhelp verify that the expected fluid is actually being used in the flowchannel 48 during a particular analysis or procedure.

The sensor 50 may be coupled to a controller (not shown) of theinstrument. The controller may send as signal to activate the sensor 50and may send a signal to deactivate the sensor 50, as desired. Inreturn, the sensor 50 may provide data about the flow rate or othercharacteristic of the fluid passing through flow channel 49, as desired,to the controller. Alternatively, or in addition, the sensor 50 may bepositioned on the cartridge 41, and may be used to, for example,directly measure the flow rate in the flow channel 48 of the cartridge41. However, this may increase the cost of the cartridge 41.

FIG. 4 is a schematic view of another illustrative fluidic analyzer thatincludes two (or more) needles 40 and 52 in the instrument/cartridgeinterface. In one illustrative embodiment, the cartridge 41 includes afirst flow channel 48 a and a second flow channel 48 b. The first flowchannel 48 a and the second flow channel 48 b are separated by a wall53, indicated in a dotted crosshatch in FIG. 4. The first needle 40 may,for example, extract a fluid from the first flow channel 48 a of thecartridge 41, and the second needle 52 may return the fluid back to thesecond flow channel 48 b of the cartridge 41. The instrument may have aflow channel 55 that fluidly connects the first needle 40 and the secondneedle 52. A flow sensor 50 may be provided in line with the flowchannel 55 of the instrument, and may provide a measure of the flow ratein the first flow channel 48 a and/or the second flow channel 48 b ofthe cartridge. By moving the flow sensor 50 to the instrument, ratherthan providing the flow sensor 50 on the cartridge 41, the cost of thecartridge 41 may be reduced. Alternatively, or in addition, the flowsensor 50 may be used to detect one or more characteristics of thefluid, such as thermal conductivity, specific heat, fluid density,electrical resistivity, and/or other characteristics of the fluid to,for example, help identify or verify that the fluid passing through thefirst flow channel 48 a and/or the second flow channel 48 b of thecartridge is the expected fluid. This may help verify that the expectedfluid is actually being used in the first flow channel 48 a and/or thesecond flow channel 48 b during a particular analysis or procedure.

During use, the first needle 40 and the second needle 52 may be insertedsimultaneously or sequentially into the cartridge 41 through theirrespective septums. Such insertion may be similar to that describedabove with reference to FIG. 2. Once both of the needles 40 and 52 areinserted into the cartridge 41, the first needle 40 may extract thefluid from the flow channel 48 a in the cartridge 41 and cause it toflow through the “off card” flow channel 55. When in the “off card” flowchannel 55, the sensor 50 may measure the flow rate (and/or othercharacteristics) of the fluid. After the flow rate is measured, thefluid may pass to the second needle 52, where it is returned to flowchannel 48 b of the cartridge 41. After the cartridge 41 is used, bothneedles 40 and 52 may be withdrawn from the cartridge 41, again similarto that described above with reference to FIG. 2.

In another illustrative embodiment, the wall 53, indicated in dottedcrosshatch in FIG. 4, may not be present. That is, both the first needle40 and the second needle 52 may access a common flow channel labeled 48.The second needle 52 may be positioned either upstream or downstream ofthe first needle 40. In this configuration, the first needle 40 maytransmit a first pressure to the sensor 50, and the second needle 52 maytransmit a second pressure to sensor 50. The sensor may be, for example,a differential pressure sensor. From the difference in pressure sensedat the two locations along the flow channel 48, the flow rate along theflow channel 48 may be determined. A restriction may be positioned inthe flow channel 48 between the first needle 40 and the second needle 52to increase the pressure drop therebetween, if desired. It iscontemplated that the needles discussed above may be provided on aremovable cartridge, and the corresponding septums may be placed on theinstrument, if desired.

FIG. 5 is a schematic partial cross-sectional side view of anotherillustrative instrument/cartridge interface. In the illustrativeembodiment, the instrument may include a plunger 60 with a relativelyrigid end 63. The plunger may be, for example, a screw, a piston, or anyother suitable device, as desired. In the case of a screw type plunger,it is contemplated that the screw may be a fine-pitch screw. However anysuitable screw be used, as desired.

In the illustrative embodiment, the plunger 60 is attached or part of aninstrument, and may be actuated up and down by an actuator. In somecases, the actuator may be controlled by an automated process. In suchcases, the instrument may include a motor (not shown), such as a microstepper motor, to control the position of the plunger 60. Alternatively,it is contemplated that under some circumstances, the actuation of theplunger 60 may be provided manually, such as, for example, by a lever,pressure button, or any other manual method, as desired.

In the illustrative embodiment, a removable cartridge 61 may have afluid storage cavity 66 defined by storage cavity 66 walls, in which, afluid may be stored. In one case, the fluid storage cavity 66 may be acylindrical shaped storage cavity 66 having a relatively larger radiusthan height so as to fit on a relatively thin disposable cartridge.However, it is contemplated that the storage cavity 66 may be anysuitable size or shaped as desired. The illustrative storage cavity 66is fluidly coupled to a flow channel 64 on the cartridge 61.

At least a portion of one or more of the walls of the storage cavity 66,in most cases, an external wall of the cartridge 61, may include amembrane 62. In some cases, the membrane 62 may be a resilient and/orflexible membrane, such as an elastomeric membrane. In some cases, themembrane 62 may be provided by first removing a portion of the cartridge61 to define an opening forming the storage cavity 66. Then, themembrane 62 may be disposed in and/or over the opening and, in somecases, over a portion of the upper surface of the cartridge 61 to form afluid tight seal.

The size of the opening may be larger than the end 63 of the plunger 60,thus, allowing the plunger 60 to deform and displace the membrane 62into the storage cavity 66. In some cases, the portion of the membrane62 that is disposed over the opening may be recessed from the uppersurface 67 of the cartridge 61. Such a recessed membrane 62 may helpprevent accidental compression or displacement of the membrane 62, whichcould lead to accidentally inducing a flow in the flow channel 64 of thecartridge 61.

The illustrative embodiment may induce a flow of fluid in the flowchannel 64 of the cartridge 61 by moving the plunger 60 against themembrane 62, deforming and displacing the membrane 62 toward the storagecavity 66, which in turn, displaces the fluid stored in the storagecavity 66 down the flow channel 64.

During use, the cartridge 61 may first be positioned in an instrument.In some cases, the instrument may align the plunger 60 with the storagecavity 66 of the cartridge 61. Next, the instrument may move the plunger60 in contact with the membrane 62, but not yet displacing the membrane62. The instrument may then drive the plunger 60 into the membrane 62,displacing the membrane 62 into the storage cavity 66, and inducing aflow in the flow channel 64 of the cartridge. The instrument may thenwithdraw the plunger 60. In some cases, the plunger 60 may be actuatedin a pulsing manner or a steady manner. More generally, it iscontemplated that the instrument may move the plunger 60 at a rateprofile that induces a desired flow rate in the flow channel 64 of thecartridge 61. In the illustrative embodiment, the membrane 62 may helpserve as a physical barrier between the instrument and the fluid in thecartridge 61. Having this barrier can reduce the risk of contaminationof the cartridge 61 and/or the instrument.

FIG. 6 is a schematic partial cross-sectional side view of yet anotherillustrative instrument/cartridge interface. This illustrativeembodiment is similar to FIG. 5, except that the plunger 70 includes aresilient and/or flexible membrane 78 that can be expanded (e.g.inflated) via fluid pressure to displace the membrane 62 into thestorage cavity 66, which in turn, induces a flow in the flow channel 64of the cartridge 61. More specifically, the plunger 70 may have a firstend that is attached to the instrument and a second end that ispositioned adjacent the membrane 62 of the cartridge 61. One or moreflow channel 79 a and 79 b may be provided in the axial direction of theplunger 70. The one or more flow channel 79 a and 79 b may form apressure conducting path between a pressure source in the instrument anda cavity behind the resilient and/or flexible membrane 78. The shaft 70may be coupled to a controller that controls the movement of the shaft70 (up/down) and/or the flow of fluid (gas or liquid) through the one ormore flow channel 79 a and 79 b shaft 70 to the cavity near the shafttip.

During use, the cartridge 61 may first be positioned in an instrument.In some cases, the instrument may align the shaft 70 with the storagecavity 66 of the cartridge 61. Next, the instrument may move the shaft70 in contact with the membrane 62, but not yet displacing the membrane62, if desired. The instrument may then inflate the cavity behind theresilient and/or flexible membrane 78 of the shaft 70, which displacesthe membrane 62 into the storage cavity 66, and induces a flow in theflow channel 64 of the cartridge 61. The instrument may then deflate thecavity behind the resilient and/or flexible membrane 78, and withdrawthe shaft 70. In some cases, the inflation of the cavity behind theresilient and/or flexible membrane 78 may be made in a pulsing manner ora steady manner. More generally, it is contemplated that the instrumentmay control the inflation of the cavity behind the resilient and/orflexible membrane 78 at a rate profile that induces a desired flow ratein the flow channel 64 of the cartridge 61. The illustrative process maybe automated or under manual control, depending on the application.

FIG. 7 is a schematic partial cross-sectional side view of anotherillustrative instrument/cartridge interface. The illustrative embodimentincludes an instrument that has a nozzle 80 for providing a desired flowrate to a flow channel 84 of a cartridge 81. The nozzle 80 may befluidly coupled to a pressure source (not shown) to provide apressurized (positive or negative) fluid (gas or liquid) to the nozzle80. The pressure source may be a pneumatic pump, a compressed gassource, or any other suitable pressure source, as desired.

The nozzle 80 may have a first end attached to the instrument and asecond end adapted to engage the cartridge 81. The cartridge 81 may havea flow channel 84 with a flow channel opening at one end. In some cases,there may be a storage cavity 86 fluidly coupled to the flow channel 84for storing a volume of fluid, such as a sample fluid (e.g. blood). Insome cases, the flow channel opening may have a one-way valve 82. Theone-way valve 82 may have characteristics that allow fluid or gas topass through in one direction, but prohibit or substantially prohibitgas or fluid to pass through in the other direction. In some cases, thevalve 82 may be configured to prevent the backflow of fluid and/or gasfrom the cartridge 81, which in some cases, may help reduce the risk ofcontamination of the instrument or surrounding space.

In some cases, the illustrative nozzle 80 may include a gasket or sealat the second end adjacent the cartridge 81. In addition, oralternatively, the cartridge 81 may include a gasket or seal around theflow channel opening of the cartridge 81. The gasket or seal may helpprovide a leak-free interface between the nozzle 80 and the cartridge81. In some cases, the seal may be airtight so that no air or fluid mayleak out. The seal may also help reduce contamination by preventingfluid from leaking out of the interface.

To induce a flow in the sample fluid, the cartridge 81 may be insertedand mounted in the instrument (see, for example, FIG. 1). In some cases,the opening in the cartridge 81 may then be aligned with the opening inthe nozzle 80. In other cases, the mounting of the cartridge 81 in theinstrument automatically ensures that the opening in the cartridge 81 issufficiently aligned with the opening in the nozzle 80. The nozzle 80may then be brought into engagement with the cartridge 81 to provide aleak-free interface therebetween. The nozzle 80 may be moved down to thecartridge 81 in an automated or manual manner. For example, a motor orthe like may be used to move the nozzle 80 into engagement with thecartridge 81. Alternatively, a user may manually move the nozzle 80 intoengagement with the cartridge 81, such as by closing a cover of theinstrument (see, for example, FIG. 1).

Once positioned and sealed, pressure may be applied by the instrumentinto the opening of the cartridge and into the flow channel 84. Thepressure may be applied by, for example, pumping fluid or gas though thenozzle 80 and into the flow channel 84. The fluid or gas pumped into theflow channel 84 may displace the fluid in the flow channel 84 and inducea flow therein. In some cases, the fluid or gas pumped into the flowchannel 84 may displace a sample fluid (e.g. blood) contained in storagecavity 86.

In some embodiments, a movable stopper or the like (not shown) may beprovided in the flow channel 84. The fluid or gas pumped into the flowchannel 84 through the nozzle 80 may be on an upstream side of thestopper, and the fluid or gas already in the flow channel 84 (e.g.sample fluid) may be on a downstream side of the stopper. The fluid orgas that is pumped into the flow channel 84 through the nozzle 80 maymove the stopper along the flow channel, thereby inducing a flow of thefluid or gas already in the flow channel 84. The stopper may separatethe fluid or gas pumped into the flow channel 84 through the nozzle 80from the fluid or gas already in the flow channel 84. This may helpprevent the fluid or gas pumped into the flow channel 84 through thenozzle 80 from mixing with the fluid or gas already in the flow channel84, when desired.

FIG. 8 is a schematic partial cross-sectional side view of anillustrative embodiment for determining a flow rate on a cartridge. Theillustrative embodiment includes a nozzle 90 and a cartridge 91, similarto that described above with respect to FIG. 7. In this embodiment, thecartridge 91 may have a flow channel 92 with at least one opening thatis adapted to be in fluid communication with the opening 96 of thenozzle 90. In some cases, a restriction 94 may be provided in the flowchannel 92 that allows a known flow rate of fluid to pass through theflow channel 92 for a given input pressure provided by nozzle 90. Therestriction 94 may be the flow channel 92 itself, or may be a separatefeature such as a reduced cross-section section of the flow channel 92.

To determine the flow rate of the fluid through the flow channel 92, thepressure on both sides of the restriction 94 may be sensed. The pressureon the nozzle 90 side of the restriction 94 may be sensed by, forexample, a pressure sensor or the like in the instrument itself. Thepressure on the downstream side of the restriction 94 may be measuredusing a pressure sensor on the cartridge. Alternatively, a pressure tap98 may be provided downstream of the restriction. The pressure tap 98may include an interface with the instrument, and the instrument mayinclude a pressure sensor to determine the pressure via the pressure tap98. The interface may include any type of instrument/cartridgeinterface, including those discussed herein. It is contemplated that,under some circumstances, multiple pressure taps may be used, asdesired.

FIG. 9 is a schematic partial cross-sectional side view of anotherillustrative embodiment for determining a flow rate on a cartridge. Thisillustrative embodiment is similar to that shown and described withreference to FIG. 8, except two pressure taps 104 and 106 are providedon the cartridge 101, one on each side of a restriction 102. Thepressure taps 104 and 106 may have an interface with the instrument,similar to that of FIG. 8. With the two known pressures, the flow rateof the fluid may be determined.

FIG. 10 is a schematic partial cross-sectional side view of anillustrative fluidic analyzer that includes a cartridge 111 with acollapsible flow channel 114 and an instrument with a roller 110 forcontrollably collapsing the flow channel 114. In the illustrativeembodiment, the cartridge 111 includes a flow channel 114 defined byflow channel 114 walls. At least one of the flow channel 114 wall mayinclude, at least in part, a collapsible membrane 112. In some cases,the collapsible membrane 112 may define at least a portion of an outerwall of the flow channel 114. Additionally, in some cases, the otherwalls of the flow channel 114 may be rigid. The illustrative membrane112 may be an elastomer or any other flexible material, as desired.Alternatively, the illustrative membrane 112 may be a fairly rigidmaterial that can be collapsed while still maintaining a fluid tightseal about the flow channel 114.

The instrument may include a roller 110 for applying a pressure to thecollapsible membrane 112 of the cartridge 111 after it is mounted in theinstrument. In one case, the roller 110 may apply a force to thecollapsible membrane 112, collapsing the flow channel 114 and continueto roll along the membrane 112, collapsing more of the flow channel 114.In another embodiment, the roller 110 may include multiple shafts thatextend toward the cartridge 111 from the instrument. The shafts engagethe collapsible membrane 112 over time, applying a force in a sequencewhere a first shaft on one end extends and collapses the membrane 112,then a next adjacent shaft collapses the membrane 112, and so on, untilall the shafts are extended and thus, the flow channel 114 is completelycollapsed. More generally, it is contemplated that the roller 110 may beany suitable device 110 for applying a force to the collapsible membrane112, as desired. It is also contemplated that the force applied by theroller 110 may be a steady force, a rolling force, a pulsing force, orany other suitable method, as desired. Furthermore, the roller 110 maybe coupled to a controller for automated control of the roller 110, oralternatively, it is contemplated that the roller 110 may be manuallycontrolled. In the automated situation, the roller 110 may be coupled toa motor or the like, which is controlled by a controller of theinstrument.

During use, the cartridge 111 may first be inserted and mounted in theinstrument so that the roller 110 is aligned with the collapsiblemembrane 112. Next, the roller 110 may be positioned adjacent themembrane 112. When ready to create a flow in the flow channel 114, theroller 110 may be activated to apply a force sufficient to collapse partof the collapsible membrane 112. The roller 110 may continue to applythe force along the length of the flow channel 114 to induce a sustainedflow in the flow channel 114. The flow rate of the sample fluid may bedetermined by the cross-sectional area of the flow channel 114 alongwith the force and speed of the roller 110.

If the collapsible membrane 112 is too flexible, the force that isapplied to one portion of the collapsible membrane 112 may cause thefluid in the flow channel 114 to create a force on another portion ofthe membrane 112, which might cause the collapsible membrane 112 tobulge out or expand to some degree. This may create a non-linearity inthe position of the roller 110 and the actual flow induced in the flowchannel 114. This non-linearity may be compensated for by calibratingthe instrument.

Alternatively, and in some cases, the collapsible membrane 112 may beadapted to not bulge or deform outward when another part of thecollapsible membrane is collapsed. For example, the collapsible membrane112 may be made from a relatively rigid material that resists suchbulging. Alternatively, or in addition, another object may be addedabove the collapsible membrane 112 to help prevent such deformation. Inthe case when the roller 110 has multiple shafts, all the shafts may belowered to at or near the collapsible membrane before applying any forceto the first shaft, so that it may prevent or substantially prevent anyunwanted outward deformation of the membrane 112.

FIG. 11 is a schematic partial cross-sectional side view of anotherillustrative fluidic analyzer that has a cartridge with a collapsibleflow channel and an instrument with a roller for controllably collapsingthe flow channel. In this illustrative embodiment, the instrument mayinclude a roller 120 that is adapted to apply a force to the cartridge121, similar to that shown and described with reference to FIG. 10. Thecartridge 121 may include a flow channel 124 defined by flow channel 124walls, including a top wall and a bottom wall. In one embodiment, theflow channel 124 may be collapsible by having a first end that is hingedso that the top wall and the bottom wall of the flow channel 124 form apivot point, as illustrated. When a force is applied to the top surfaceof the flow channel 124, the hinge may allow the top surface to collapsetoward the bottom surface, squeezing the fluid down the flow channel124. In some cases, the top surface of the flow channel 124 may have arigid structure surrounded by a flexible membrane 122, such as anelastic membrane 122, so that when exposed to a force, the membrane 122allows the top surface to come into contact with the bottom surface.More generally, it is contemplated that any suitable method ofcollapsing the flow channel 124 may be used, as desired.

FIG. 12 is a schematic top view of a cartridge that includes a number ofgears for inducing a flow in a flow channel of the cartridge. Theillustrative embodiment includes a cartridge 131 having a flow channel136 with a chamber 138. The chamber 138 includes a number of gears 132and 134. The gears 132 and 134 may form a pump that is capable ofpumping fluid to induce a flow in the flow channel 136. In some cases,each gear 132, 134 may have multiple paddle-like structures around theperiphery of the gear. The paddle-like structures may help push thefluid through the chamber 138. As illustrated, the two gears 132 and 134may rotate in opposite directions of each other and may either push thesample fluid around the outside of the chamber 138 or between the gears132 and 134. More generally, it is contemplated that one, two, three, orany number of gears 132 and 134 may be used, as desired, to create thedesired flow.

In some cases, the gears 132 and 134 may be driven by a motor and ashaft. In other cases, the gears 132 and 134 may be driven by electricalor magnetic fields. More generally, it is contemplated that the gears132 and 134 may be driven by any suitable method.

In the illustrative embodiment, the instrument may include at least partof the driving mechanism for the gears 132 and 134. For example, theinstrument may include a motor and a shaft, wherein the shaft interfaceswith one or more of the gears 132 and 134. Alternatively, the gears 132and 134 may include a ferrous material or even be magnetized, and theinstrument may provide a rotating magnetic field that drives the gears132 and 134. The driving mechanism of the instrument may be controlledby a controller. The controller may control the operation of the gears132 and 134, such as, for example, the starting and stopping of thegears 132 and 134, the speed of rotation of the gears 132 and 134, therotational direction of the gears 132 and 134, and/or any otherparameters, as desired.

FIG. 13 is a schematic view of an illustrative fluidic analyzer thatincludes an instrument with a detector for determining the flow rateand/or current position of a fluid in a flow channel of a cartridge. Theillustrative embodiment includes a cartridge 141 having a flow channel140. A detector 142 may be provided in the instrument. In oneembodiment, the detector 142 may be mounted in the instrument adjacentthe flow channel 140 of the cartridge 141. The detector 142 may detectthe presence or certain characteristics of the fluid, either optically,electrically, magnetically, or by any other suitable method. In somecases, such as for optical detection, the cartridge 141 may provide awindow for the detector 142 to view the fluid in the flow channel 140.It is contemplated that the detector 142 may be coupled to a controllerfor activating and deactivating the detector 142, and/or for receivingdata from the detector 142.

In some cases, and to measure the flow rate of the sample fluid 144 inthe cartridge 141, there may be another fluid, such as a pusher fluid146, that pushes the sample fluid 144 through the cartridge 141. Thepusher fluid 146 may be provided to the cartridge 141 by any methodpreviously discussed or any other suitable method, as desired.Additionally, the pusher fluid 146 may include some detectablecharacteristics to be measured by the detector 142, such as, forexample, particles that can be detected either optically, electrically,or magnetically. Thus, to determine the flow rate of the sample fluid144, the flow rate of the pusher fluid 146 may be detected anddetermined.

A similar approach may be used to determine when a fluid reaches a pointalong a flow channel. That is, the detector 142 may be positionedadjacent a location along a flow channel, and the detector 142 maydetect the presence of a fluid at the location, either optically,electrically, or magnetically, as desired. This may be used to, forexample, detect when a sample fluid such as blood has sufficientlyfilled a sample fluid input channel, when a sheath or lysing fluid hasreached a certain point in a fluidic circuit on the cartridge 141, orfor any other suitable purpose, as desired.

FIGS. 14A-14B are schematic views of an illustrative fluidic analyzerthat includes an instrument with two (or more) detectors for determiningthe flow rate and/or current position of a fluid in a flow channel of acartridge. The illustrative embodiment includes two detectors 152 and154 attached to an instrument. A cartridge 151 is also provided thatincludes a flow channel 150. Similar to FIG. 13, the detectors 152 and154 may detect the presence and/or flow rate of the fluid in the flowchannel 150 either optically, electrically, magnetically, or by anyother suitable method, as desired. In some cases, the cartridge 151 mayhave two or more windows for the flow channel 150 to view the fluid inthe flow channel 150. The two or more sensor may be provided at a knowndistance apart from each other. Each sensor may be coupled to acontroller to receive and/or transmit data to and from the detectors 152and 154, as desired.

The fluid flow rate through the flow channel 150 may be determined by,for example, providing a flow down the flow channel 156. In some cases,the flow may be provided by pushing a fluid 158 with a gas 156, such as,for example, air. In the illustrative embodiment, the gas 156 or air maybe used to push the fluid so that the end of the sample fluid 158 may beeasy to detect, but this is not required. The two or more detectors 152and 154 may used to determine the flow rate of the fluid 158 by, forexample, detecting when all or substantially all of the sample fluid 158passes by each detector. A controller may determines the time lapse forthe fluid 158 to pass by each detector 152 and 154, and knowing thedistance between the detectors 152 and 154, determine the flow rate ofthe fluid 158. The illustrative point in time when the first detector152 detects the end of the sample fluid 158 is illustrated in FIG. 14A.The illustrative point in time when the second detector 154 detects theend of the sample fluid 158 is illustrated in FIG. 14B. Alternatively,or in addition, the first and second detectors 152 and 154 may be usedto detect when a sample fluid 158 first arrives to determine flow rate.In yet another embodiment, the first and second detectors 152 and 154may be used to detect some other characteristic of the fluid, such astemperature, thermal conductivity or the like. A thermal pulse may becreated in the fluid, which can then be detected by the detectors.Resistivity and/or other characteristics of the fluid may also bedetected by detectors 152 and 154. Also, the fluid may containparticles, such as beads or the like, that can be detected optically,electrically, or magnetically, to help determine the flow rate of thefluid. It is contemplated that more than two sensors, or only onesensor, can be used, depending on the application.

Having thus described the preferred embodiments of the presentinvention, those of skill in the art will readily appreciate that yetother embodiments may be made and used within the scope of the claimshereto attached. Numerous advantages of the invention covered by thisdocument have been set forth in the foregoing description. It will beunderstood, however, that this disclosure is, in many respect, onlyillustrative. Changes may be made in details, particularly in matters ofshape, size, and arrangement of parts without exceeding the scope of theinvention. The invention's scope is, of course, defined in the languagein which the appended claims are expressed.

1. A fluidic analyzer for supporting a flow cytometry analysis of asample fluid, comprising: a cartridge having a first major surface andan opposing second major surface, and a first flow channel defined byflow channel walls, the first flow channel situated between the firstand second major surfaces such that fluid in the flow channel flowsalong a plane that is substantially parallel to planes of the first andsecond major surfaces, wherein a first opening extends from outside ofthe cartridge through the first major surface, through a flow channelwall and into the first flow channel, the cartridge including one ormore transparent windows aligned with at least part of the first flowchannel; a first septum disposed in or over the first opening andsecured to at least a portion of the cartridge with a fluid tight seal;an instrument for receiving the cartridge, the instrument having one ormore light sources and light detectors optically aligned with one ormore transparent windows of the cartridge when the cartridge is receivedby the instrument; a first needle attached to the instrument, whereinthe first needle is sized to fit in the first opening of the first flowchannel, wherein as the cartridge is received by the instrument, thefirst needle moves relative to the cartridge from a first retractedposition where the first needle does not pierce through the first septumof the cartridge, to a second extended position where the first needlepierces through the first septum, extends into the first opening of thecartridge, and is in fluid communication with the first flow channel; aflow sensor in line with the first needle and configured to detect ameasure related to a flow rate of fluid passing through the firstneedle; the instrument in communication with the flow sensor andconfigured to induce and control a flow rate of a fluid in the firstneedle, which in turn, induces and controls a flow rate of fluid in thefirst flow channel of the cartridge when the first needle is situated inthe first opening of the first flow channel and through the first septumin the second extended position, the flow rate of fluid in the firstflow channel of the cartridge configured to support the flow cytometryanalysis of the sample fluid; and the instrument structured to performat least some of the flow cytometry analysis of the sample fluid byoptically analyzing a fluid as the fluid flows through the first flowchannel adjacent the at least one of the one or more transparent windowsof the cartridge.
 2. The fluidic analyzer of claim 1 wherein the firstneedle includes a body and a tip, and also a stopping mechanism that isdisposed around at least part of the body of the first needle andextends laterally away from the body of the first needle, the stoppingmechanism also being offset from the tip of the first needle.
 3. Thefluidic analyzer of claim 2 wherein the stopping mechanism is offsetback from the tip of the first needle by a distance that allows the tipof the first needle to pierce through the first septum in the secondextended position, while preventing the tip of the first needle fromengaging a back side of the first flow channel.
 4. The fluidic analyzerof claim 1 wherein the first septum includes a resilient and/or flexiblematerial that extends over the first opening and overlaps and is securedto at least part of the first major surface adjacent to the firstopening of the cartridge.
 5. The fluidic analyzer of claim 1 wherein:the first needle is configured to pierce the first septum in the secondextended position, and provide a fluid to the first flow channel of thecartridge; and the first septum is configured to provide a relativelyfluid tight seal around the first needle when the first needle piercesand extends through the first septum in the second extended position. 6.The fluidic analyzer of claim 1 wherein the first septum is configuredto allow the first needle to pierce the first septum in the secondextended position, and reseal or substantially reseal the first openingafter the first needle is withdrawn from the first septum in the firstretracted position.
 7. The fluidic analyzer of claim 6 wherein the firstseptum provides a substantially leak-free seal around the first needlewhile the first needle pierces and extends through the first septum inthe second extended position, and wipes off residual fluid from thefirst needle as the first needle is withdrawn from the first septumtoward the second extended position.
 8. The fluidic analyzer of claim 1wherein a sample fluid is introduced into the cartridge, and the inducedflow in the first flow channel induces a flow rate in the sample fluid.9. The fluidic analyzer of claim 8, wherein the instrument adjusts theinduced flow in the first flow channel to produce a desired flow rate inthe sample fluid.
 10. The fluidic analyzer of claim 1, wherein the flowsensor is in the instrument.
 11. The fluidic analyzer of claim 10wherein the flow rate through the first needle is related to the flowrate through the first flow channel of the cartridge.
 12. The fluidicanalyzer of claim 1, wherein the instrument includes a sensor to senseone or more characteristics of the fluid and to help identify whetherthe flow of fluid induced in the first needle is a desired fluid. 13.The fluidic analyzer of claim 1, wherein the cartridge includes a secondflow channel, and the instrument includes a second needle that passesfluid between the second flow channel of the cartridge and theinstrument.
 14. The fluidic analyzer of claim 13, wherein the secondneedle is in fluid, communication with the first needle via a fluidpathway of the instrument.
 15. The fluidic analyzer of claim 14, whereinthe instrument includes a flow sensor for sensing the fluid in the fluidpathway between the first and second needles.
 16. The fluidic analyzerof claim 1, wherein: the cartridge has a second flow channel defined byflow channel walls, wherein a second opening extends from outside of thecartridge and into the second flow channel; a second septum disposed inor over the second opening and secured to at least a portion of thecartridge with a fluid tight seal; a second needle attached to theinstrument, wherein the second needle is sized to fit in the secondopening of the second flow channel, wherein as the cartridge is receivedby the instrument, the second needle moves relative to the cartridgefrom a first retracted position where the second needle does not piercethrough the second septum of the cartridge, to a second extendedposition where the second needle pierces through the second septum,extends into the second opening of the cartridge, and is in fluidcommunication with the second flow channel; and the instrument isconfigured to induce a flow in the second needle, which in turn, inducesa flow in the second flow channel of the cartridge when the secondneedle is situated in the second opening of the second flow channel andthrough the second septum in the second extended position.
 17. Thefluidic analyzer of claim 1, wherein the fluid analyzer includes ahematology analyzer.
 18. The fluidic analyzer of claim 1, wherein thefluid analyzer includes a flow cytometer.
 19. The fluidic analyzer ofclaim 1, wherein the fluid analyzer includes a clinical chemistryanalyzer.
 20. The fluidic analyzer of claim 1, wherein the fluidanalyzer includes a urine analyzer.
 21. The fluidic analyzer of claim 1,wherein the instrument includes a second needle that passes fluidbetween the instrument and the flow channel of the cartridge.
 22. Afluidic analyzer for supporting a flow cytometry analysis of a samplefluid, comprising: a cartridge having at least one flow channel definedby flow channel walls, wherein first and second spaced apart openingsextend from outside of the cartridge and into one or more of the flowchannels, the cartridge including one or more transparent windowsaligned with at least part of one or more of the flow channels, thecartridge having a hydrodynamic focusing region; a first septum disposedin or over the first opening and secured to at least a portion of thecartridge with a fluid tight seal, and a second septum disposed in orover the second opening and secured to at least a portion of thecartridge with a fluid tight seal; an instrument for receiving thecartridge, the instrument having one or more light sources and lightdetectors optically aligned with the one or more transparent windows ofthe cartridge when the cartridge is received by the instrument; firstand second needles attached to the instrument, wherein the first needleis sized to fit in the first opening of the flow channel and piercethrough the first septum when the cartridge is received by theinstrument, and the second needle is sized to fit in the second openingof the flow channel and pierce through the second septum when thecartridge is received by the instrument; an instrument flow channel inthe instrument fluidly connecting the first and second needles; a flowsensor configured to detect a measure related to a flow rate of fluidpassing through the instrument flow channel; the instrument coupled tothe flow sensor and configured to induce and control a flow rate of afluid in one or more of the flow channels of the cartridge when thefirst and second needles are situated in the first and second openingsof the flow channel and through the first and second septums,respectively, the flow rate configured to support the flow cytometryanalysis of the sample fluid, the instrument structured to extract fluidthrough the first needle from at least one flow channel in thecartridge, to transport the fluid from the first needle through theinstrument flow channel to the second needle, and to return the fluid toat least one flow channel in the cartridge through the second needle;and the instrument structured to perform at least some of the flowcytometry analysis of the sample fluid by optically analyzing a fluid asthe fluid flows through one or more of the flow channels adjacent theone or more transparent windows of the cartridge.
 23. A method forsupporting a fluid analysis of a sample fluid having cells, the methodcomprising: providing a disposable cartridge including one or moretransparent windows and at least first and second flow channels, whereinthe one or more transparent windows are aligned with an interrogationregion that is in fluid communication with the first and second flowchannels, wherein a first opening extends from outside of the disposablecartridge through a flow channel wall and into the first flow channel,wherein a second opening extends from outside of the disposablecartridge through a flow channel wall and into the second flow channel,the disposable cartridge having a first septum positioned in or over thefirst opening, and a second septum positioned in or over the secondopening; providing an instrument including one or more light sources andlight detectors optically aligned with the one or more transparentwindows, the instrument including first and second needles each forproviding a corresponding fluid flow; inserting the disposable cartridgeinto the instrument; the instrument moving the first needle into thefirst flow channel through the first septum and the first opening, andmoving the second needle into the second flow channel through the secondseptum and the second opening in the cartridge such that the first andsecond needles are in fluid communication with the corresponding ones ofthe first and second flow channels of the cartridge; the instrumentproviding a relative flow of fluid between the first and second needlesinto the first and second flow channels of the cartridge to provide adesired flow rate through each of the first and second flow channels tosupport the fluid analysis of the sample; the instrument performing atleast some of the fluid analysis of the sample fluid by opticallyanalyzing the sample fluid in the interrogation region through the oneor more transparent windows of the cartridge; and the instrumentwithdrawing the first and second needles from the septa and thecartridge.
 24. The method of claim 23, wherein each needle includes abody, a tip, and a stopping mechanism, wherein the stopping mechanism isprovided around at least part of the body of the needle and extendslaterally outward from the needle, the stopping mechanism being offsetback from the tip of the needle, the moving step further comprising:inserting each needle into the corresponding flow channel of thecartridge through the corresponding septum until the stopping mechanismengages the cartridge.
 25. The method of claim 24, wherein each stoppingmechanism is offset back from the tip of its needle by a distance thatallows the tip of the needle to pierce through the corresponding septumwhile preventing the tip of the needle from engaging a back flow channelwall of the flow channel when the stopping mechanism engages thecartridge.